21110011988 has 48 divisors (see below), whose sum is σ = 40083696576. Its totient is φ = 9669922560.

The previous prime is 21110011969. The next prime is 21110011991. The reversal of 21110011988 is 88911001112.

It is a super-2 number, since 2×21110011988² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8754503 + ... + 8756913.

It is an arithmetic number, because the mean of its divisors is an integer number (835077012).

Almost surely, 2^21110011988 is an apocalyptic number.

It is an amenable number.

21110011988 is a deficient number, since it is larger than the sum of its proper divisors (18973684588).

21110011988 is a wasteful number, since it uses less digits than its factorization.

21110011988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3624 (or 3622 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 32.

The spelling of 21110011988 in words is "twenty-one billion, one hundred ten million, eleven thousand, nine hundred eighty-eight".